Determination Of Process-dependent Critical SPICE Parameters For Application-specific ICs

Abstract

The sensitivity analysis results are of fundamental importance to the VLSI design because it provides the information to identify a set of critical parameters for each fabrication technology. We have formulated a new sensitivity function to select the critical MOS parameters for digital and analog circuit designs using various MOSIS fabrication technologies. The most sensitive parameters with respect to the drain current have been found to be the gate-oxide thickness, threshold voltage, mobility, and body-effect coefficient. As for the transistor output conductance, the channel-length modulation coefficient and saturated carrier velocity are the most sensitive parameters in addition to those parameters mentioned above. The set of critical parameters plays an important role in the statistical circuit analysis where the worst/best-case parameter files have to be established and in the extreme-temperature circuit simulation.

Explicit geometry dependence of MOS transistor parameters by the pseudoboundary method

“…Knowledge of device physics and MOS transistor models greatly helps in the selection of the constraint values on the parameter space. The cost function can be either the drain current error or a weighted combination of errors of the drain current and conductances [28]. Parameter perturbation schemes and temperature cooling rates must also be developed.…”

Effective parameter extraction using multiple-objective function for VLSI circuits

“…Effective circuit design using an MOS transistor model depends upon the extracted model parameters. In addition to the minimization of the drain current error, it is necessary to optimize other quantities such as the transistor conductances and capacitances that are important for the accuracy of circuit simulation [9]. A significant part of the modeling effort is the extraction of model parameters for characterization of fabrication technologies.…”